We covered all the shows and exhibits in 1 day. Of course we skipped the rides. My kids are too big for the kiddie park and too chicken for the big rides yet. We didn't rush and had plenty of time to have lunch, a few snacks and take in the sites. We didn't arrive at opening, but did stay until close. We were there this year on Memorial Day, so it wasn't uncrowded. The ticket line was our worse wait at over 30 minutes.
All of the shows have something fun about them. Honestly, my least favorite is Blue Horizons. And while it's probably not really "sea" themed, my kids love the Pets Ahoy show the best. It's full of cats and dogs and very cute and fun. The sea lions show is fun too, especially the night show. Try to make that one if you can only see them once. And no visit is complete without Shamu. I agree the Shamu Rocks is the better of the two, but we did do them both. My kids aren't satisfied their visit to SW is complete until they've been soaked by a killer whale.
regards